Sound recording



May 5, 1931. L. A. TAYLOR 1,804,289

SOUND RECORDING Filed Jan. 31, 1930 lrlventor Laurens ATE-=15 lor" H is Attohn eg.

Penna-e May 5, 931

umrsosmrss PATENT" OFFICE mums A. mama, or scnnnnornnr; NEW YORK, assremon r amass nnncrnrc J comm, A conronn'rrox or NEW Yomz I souzm nnconnme Application filed January :1, 1930. serial are. 424,992.

My invention relates to apparatus for photographicallyrecording sound, and an object of my apparatus of this character of improved means for monitoring therecording opera tion. Y

My. invention will be better understood from the following description taken in con nection' with the accompanying drawing,

19 and its scope will be pointed out in the appended claims.

Referring to the drawing in which the single figure shows in a diagrammatic manner one embodiment of my invention, the

lsensitive film upon whichthe sound is to be recorded is shown at 1 as being supported on the surface of the rotatable drum 2. The sound may be recorded on the film either in accordance with the variable intensi method or the variable width method. In the present illustration I have chosen to show well known means for making a record V of the variable width 't emplo 'ng an oscillograph galvanometei d f which b nly the moving portion is shown. This meanscomprises the light source 4, lens 5, stop 6 having opening 7, galvanometer mirror 8 mounted on the conductor loop 9 of the galvanometer, the cylindrical lens 10, lens 11, stop 12 having the aperture or slit 13- therein, and objective 14. The

vibration of the mirror 8 in accordance with the sound waves causes the concentrated refiected light beam to illuminate more or less.

or the aperture 13 in stop 12. Objective 14 focuses a reduced image of the illuminated portion of aperture 13 on the film. The two vertical edges of the opening 7 in stop 6 give the light beam two opposite sharply defined working edges. en there is no sound the galvanometer is usually adjusted to bring one of those edges approximately at the middle of aperture 13. A certain portion of the beam reflected by the mirror always passes to one side of the cylindrical lens 10 and since it does not reach the film is in efiect lost. In accordance with my invention,'I make use or this unused portion of the light beam for monitoring purposes and by so doing enable the operator to obinvention is the provision in cylindrical lens the stop 17 having the opening 18 I much greater than track and the distance between mirror 16 andnot only may be observed tain a true indication of the operation of the pick-up, the amplifying apparatus and the gal'vanometer without in any way interfering with the making of the record.

At a point between the mirror and the 10, latter, I mopnt the Imrror 16 1n such a osition that it will reflect that part of the ht beam which would not reach the film ut will not intercept any of the light which otherwise would reach the film. In the path of the light reflected by mirror 16 I place therein through which most of the light passes. The upper portion of the stop 17 is provided with a scale by means of which the amplitude of vibration -of the yreflected beam can be read ofi. The length of the opening 18 is the width of the sound stop 17 is such that the movement ofthe am engaging the stop is greater in the same proportion than the movement of the beam engaging the film. By observing the amplitude of vibration of the beam directed on the stop the operatofmay become aware of and guard against any overshootin of the limits of the sound track b beam. Observation of the vi ration am litude is facilitated by reason of the fact t at that portion of therbeam reflected by the' galvanometer mirror has one of the two working edges mentioned above, this edge, when there is no sound, extendin middle of the opening 18; The ight which passes through the opening 18 is collected by the lens 19 preferably close to the the-recur g".

across the and is received by the photo-elec- I tric cell 20. A sound producing device suitable for monitoring purposes such for example as the loud through a suitable thermionic amplifier 22 speaker 21 is connected with the terminals of the cell 20. With the above proportionality betweembeam movements, length of stop and width of the sound track, overshooting of the sound track but the efi'ect thereof may be heard in the loud s aker.

In makin ratus the operator is *able to monitorthe operation of the various elements of-the rega sound record with t 's appacording mechanism from the sound pick-up light source,

to the variable exposing light both audibly and visually and this without any sacrifice in the efiioiencyot the recording apparatus.

What I claim as new and desire to secure b l. Apparatus for recording sound on a moving light sensitive member comprising a means for laterally vibrating a beam of light from said source in accordance with sound waves, means whereby the light comprising one portion of said beam mag expose said member, monitoring means, an means arranged to direct the light comprising another portion of said beam toward said monitoring means and to cause a magnification of the movement thereof.

2. Apparatus for recording sound on a moving light sensitive member comprising a light source, means for laterally vibrating a beam of light from said source in accordance with sound waves, a member having an o ening therein through which a portion of t e vibrated beam passes to said light sensitive member, a monitoring device, and a mirror arranged to reflect toward. said device a portion of the vibrated beam normally not passing said opening.

3. Apparatus for recording sound on a moving light sensitive member comprising a light source, means for vibrating a beam of light from said source transverse of said moving member in accordance with sound waves, means by vibrated beam is used to expose said light sensitive member, and monitoring apparatus comprising visual and audible indicating means arranged to be operated by a portion not used to expose the light sensitive member.

4. Apparatus for recording sound on a moving film comprising a light source, a mirror res onsive to sound waves for vibrating a beam of light from said source transversely of said film, means for-focusing a portion of the vibrated beam on the film, means for deflectin another portion of the vibrated beam, and monitoring apparatus arranged to be affected by said other ortion, said apparatus comprising means or visually indicating the amplitude of the recorded sound and means for audibly indicating the quality thereof.

5. Apparatus for recording sound on a moving film comprising a lightsource, a mirror responsive to sound waves for vibrating a beam of light from said source transversely of said film, a stop between the mirror aiid the film having a narrow aperture therein, means for imaging said aperture on the film, a second stop having a scale thereon and an opening therein, a mirror arranged to reflect on said second stop a portion of the vibrated beam not used, for recording on the film, a photo- Letters Patent of the United States is 2- which a portion of said electric cell arranged behind the aperture in said stop and a sound producer connected with said cell. 6. Apparatus for recording sound on a moving film comprising .a light source, a mirror responsive to sound waves for vibrating a beam of light from said source transversely of said film, a stop between the mirror and the film having a narrow aperture therein, means for imaging said aperture on the film, scale thereon and an opening therein, a mirror arranged to reflect on said second stop a portion of the vibrated beam not used for recording on the film, a photoelectric cell arranged behind the openmg in said second 'stop, and a sound producer connected with said cell, the apparatus being so constructed and arranged that the movement of the beam engaging said second stop and the length'of the opening in said stop are proportional to the movement of the film exposing beam and the width of the sound track.

a second stop having a- In witness whereof, I have hereunto set 

